Wastewater Treatment Operator
Certification Exam | Comprehensive
Questions and Verified Answers Graded
A+
What is the typical removal efficiency of total suspended solids in the
primary clarifier?
A) 95 to 99%
B) 20 to 50%
C) 10 to 15%
D) 40 to 60% - Correct Answer > D) 40 to 60% (v.1 pg 129)
How does temperature affect the activity of microorganisms in a an
aeration tank?
A) Low microorganism growth rate as temperature increases
B) Rapid microorganism growth rate as the temperature increases
C) Does not affect activity of microorganisms
,D) Decrease in temperature will result in more biological activity -
Correct Answer > B) Rapid microorganism growth rate as the
temperature increases (v.2 pg 71)
What is the purpose of air input for an aerated grit chamber?
A) Helps remove TDS
B) Air improves the disinfection process
C) Freshens wastewater and helps separate grit and other solids
D) Addresses denitrification - Correct Answer > C) Freshens
wastewater and helps separate grit and other solids (v.1 pg 42)
What change would most likely be made to an activated sludge process
during the winter?
A) Decrease solids under aeration
B) Increase pH
C) Increase solids under aeration
D) Add chlorine to the influent of the aeration tank - Correct
Answer > C) Increase solids under aeration (v.2 pg 71)
Which of the following is the most abundant in an anaerobic digester?
, A) Carbon dioxide
B) Nitrogen
C) Methane
D) Hydrogen sulfide - Correct Answer > C) Methane (v.2 pg 158)
What might cause brown or black scum to appear on the surface of a
pond?
A) Low BOD loading
B) Pond is overloading (BOD)
C) Storm
D) Periods of high runoff - Correct Answer > B) Pond is
overloading (BOD) (v.1 pg 308)
What happens when there are many air bubbles in the water of an
operating pump?
A) Water hammer
B) Cavitation
C) Less noise generated by the pump
D) More efficient pumping - Correct Answer > B) Cavitation (v.2
pg 346)
Certification Exam | Comprehensive
Questions and Verified Answers Graded
A+
What is the typical removal efficiency of total suspended solids in the
primary clarifier?
A) 95 to 99%
B) 20 to 50%
C) 10 to 15%
D) 40 to 60% - Correct Answer > D) 40 to 60% (v.1 pg 129)
How does temperature affect the activity of microorganisms in a an
aeration tank?
A) Low microorganism growth rate as temperature increases
B) Rapid microorganism growth rate as the temperature increases
C) Does not affect activity of microorganisms
,D) Decrease in temperature will result in more biological activity -
Correct Answer > B) Rapid microorganism growth rate as the
temperature increases (v.2 pg 71)
What is the purpose of air input for an aerated grit chamber?
A) Helps remove TDS
B) Air improves the disinfection process
C) Freshens wastewater and helps separate grit and other solids
D) Addresses denitrification - Correct Answer > C) Freshens
wastewater and helps separate grit and other solids (v.1 pg 42)
What change would most likely be made to an activated sludge process
during the winter?
A) Decrease solids under aeration
B) Increase pH
C) Increase solids under aeration
D) Add chlorine to the influent of the aeration tank - Correct
Answer > C) Increase solids under aeration (v.2 pg 71)
Which of the following is the most abundant in an anaerobic digester?
, A) Carbon dioxide
B) Nitrogen
C) Methane
D) Hydrogen sulfide - Correct Answer > C) Methane (v.2 pg 158)
What might cause brown or black scum to appear on the surface of a
pond?
A) Low BOD loading
B) Pond is overloading (BOD)
C) Storm
D) Periods of high runoff - Correct Answer > B) Pond is
overloading (BOD) (v.1 pg 308)
What happens when there are many air bubbles in the water of an
operating pump?
A) Water hammer
B) Cavitation
C) Less noise generated by the pump
D) More efficient pumping - Correct Answer > B) Cavitation (v.2
pg 346)
